Athletic performance is a function of both an athlete's physical condition as well as cognitive condition. Many sports demand that the athlete accurately perceive and respond to the position and motion (such as velocity, acceleration, deceleration) of teammates, competitors, and sport-specific objects such as footballs, basketballs, baseballs, pucks, or other objects in both central fields of vision and peripheral fields of vision. In order to increase personal performance, athletes have become interested in vision training as another avenue toward enhanced performance. For example, baseball batters want to improve their vision in general, and their central field of vision in particular, so at to be able to see the seams on a 90+ mph fastball. An additional example includes an American football receiver that is attempting to catch an incoming football may look over his should while maintaining his running stride. While looking over a shoulder to identify the incoming football, the receiver may be relying on a portion of his peripheral field of vision. Therefore, athletes are targeting achieving superior visual dexterity in both central field of view and peripheral fields of view to complement their physical dexterity.
A flat lens that is generally parallel to a wearer's frontal plane and offset from the wearer's eyes may cause an angle of peripheral view perceived through the lens to be reduced. Consequently, flat lenses may cause a wearer to re-orient his or her head in order to receive the intended benefit (e.g., optical correction, controlled spectral transmittance) of the lenses in portions of the peripheral field of vision that are not perceived without reorientation. Additionally, a flat lens that is angled within a curved frame, to increase an amount of peripheral field of vision, may cause eyelash contact between the wearer's eyelashes and the flat lens. Additionally, angling a flat lens within a curved frame may also introduce distortion of the central field of view as an object in the central field of view will be perceived through a greater angle of the lens resulting in an image shift as perceived by the wearer (e.g., as opposed to viewing an object directly in front of a wearer at a normal angle through the lens, the object will be perceived through the lens at the angle the lens is positioned within the frame). Angling of a flat lens within a curved frame also limits the variety of wearer head forms that comfortably fit the eyewear.